Rotating seesaw



A. E. PROBST ROTATING SEESAW @cik, 31, 1950 3 Sheets-Sheet l Filed March 17, 1948 INVENTOR Arthur E. PreDhSi BY W ATTORNEYS A. E. PROBST ROTATING SEESAW Ed. BE, 1195@ 3 SheetsSheet 2 Filed March 17, 1948 INVENTOR Arthur E. Pw@%st ATTONEYS A. E. PROBST ROTATING SEESAW @c&. 31, 1950 3 Sheets-Sheet 5 Filed March 17, 1948 INVENTOR Arthur E. Prolrst ATTORNEYS Patented Oct. 31, 1950 UNITED STATES PATENT:

OFFICE 4 Claims.

The present invention relates to teeter-totters which can be used outdoors in gardens or playgrounds or in other places of amusement, and more particularly to teeter-totters which can be used as merry-go-rounds.

The board II is provided with conventional hand grabs i5, as shown, for example, in Fig. 1.

Amusement devices of this general character,

especially teeter-totters, have had one serious disadvantage in that it has been necessary for the persons to be of similar we ght, for otherwise the exertion required for movement of the teetertotter must me made almost entirely by the heavier of the two persons.

According to the present invention, a teetertotter device is provided which can be used as a conventional teeter-totter or see-saw or as a merry-go-round and, if desired, the two movefeatures of the present invention is a control mechanism which enables the device to be enjoyed by persons whose weights are quite different. Another feature of the invention is that the device is so constructed that there is substantially no danger of accidental injury to small children.

Other features of the invention will become ap- A plate I6, (Fig. 6) is secured beneath the central portion of the board II and has depending arcuate flanges H which extend downwardly from the edges of the board I I to enclose the upper portion of the supporting and rotating mechanism so as to prevent accidental injury by the moving parts of the teeter-totter. Each of the flanges I1 is provided with a semi-cylindrical portion I8 of'a clamp adapted to cooperate with a second semi-cylindrical portion I9 for securing the flanges I I and hence the board I I to the axle I2. The portions I9 are removably bolted to the portions I8, as shown in Fig. 3, to facilitate mounting the board on the axle I2. ments can be combined. One of the principal With particular reference to Fig. 6, the axle I2 is rotatably mounted in the bearing I3 which, in turn, is secured to the top of shaft I4, for example by a threaded connection. An annular plate 20 is secured, as by welding, to the inside parent from the following detailed description of of shaft I4. A bearing stud 2I is mounted in the aprture of plate 20 and loosely secured thereto, for example, by means of a cotter pin 22. The bearing stud 2! rests on a bushing 23 disposed within a housing 24 which is secured to the inside of a fixed hollow shaft 25. The shaft 25 is concentrically arranged within hollow shaft I4 and extends down into the ground for supporting the teeter-totter. The bushing 23 and bearing stud 2I permit rotation of the board in a horizontal plane when used as a merry-go-round. A side of a mechanism for controlling the operation of the device,

Fig. 6 is an enlarged end view of the device partly in elevation and partly in vertical crosssection,

Fig. 7 is an elevation, partly in vertical crosssection, of a detail for optionally preventing the device from being used as a merry-go-round, and

Fig. 8 is a horizontal cross-sectional view taken along line 8-8 of Fig. 6, showing a portion of the support for the teeter-totter.

As shown in Figs. 1, 3 and 6, a board II is secured to an axle I2 which is rotatably supported in a bearing I3 (see Fig. 6) secured to the upper end of a vertical hollow shaft I 4. This enables the board to be rocked or tilted in a vertical plane about the horizontal axis of the axle I2 to give the desired see-saw motion. The vertical shaft [4, as described more fully hereinafter, is rotatable about its vertical axis, thus permitting the desired merry-go-round motion.

thrust bearing 25a, comprising an enlargemnt of or a ring disposed around the shaft 25, is provided to minimize side play btween shaft I4 and shaft 25.

The shaft 25, as seen in Fig.1, is set into the ground in a cement filling 26. An annular flange 2! secured to the shaft 25 is embedded in the cement 2'6 to hold the shaft 25 firmly in place.

The lower end of shaft I4 is provided with a circular platform 28 which is positioned just above the level of the ground and will rotate when the teeter-totter is used as a merry-go-round. Guard plates 29, as shown in Figs. 1, 3 and 6, are secured to the platform 28 and extend upwardly beyond the curved edge of flanges I'I so as to enclose the moving parts of the device. These guard plates 29 include end pieces (see Fig. 3) which completely enclose the lower portion of the shaft I4 and the lower portions of two spring control mechanisms 30, as seen in Figs. 1, 2 and 3.

The control mechanisms 30 are movably secured at their upper ends to brackets 3! on the underside of the board I I, as shown in Figs. 1 and 6 and are adjustably secured to a bracket 32 fixed to the platform 28 and the shaft l4, as shown in Fig. 1. When the board II is tilted, for example clockwise as shown in Fig. 2, the control mechanisms 30 will be contracted and expanded respectively, as shown in Fig. 2.

With reference to Figures 4. and 5, wherein the details of the control mechanisms 30 are shown, it will be seen that each mechanism comprises a cylinder 33, a piston 34 slidable therein and a pair of oppositely acting compression coil springs 35 and 36. The top of each cylinder 33 is provided with a cap 3'! which is adapted to be pivotally connected to one of the brackets 3lsecured to the board l I and which also serves as a retaining cup for the upper compression spring 35. A retaining cup 3? for spring 3t is secured to the lower end of the cylinder 33, said. cup 3'! being provided with a hole to receive a connecting rod 38 attached to the piston 3 The lower end of rod 38 is aflixed to the bracket 32.

The piston 34 comprises an annular disc 34a of some resilient material such as felt, which is supported on the threaded end of rod 38 by means of double lock nuts 39 and 4B. Washers 4i and 42 are disposed between the bolts 39 and 43 and the ends of springs 35 and 36 respectively as shown in Figures 4 and 5.

When the teeter-totter is not in use, the board will assume a position substantially horizontal, as shown in Figure 1, since in this position the springs 35 of, both control mechanisms exert equal pressure on their respective pistons and springs 36 are under no compression. This position of est is shown in Figure. 4. When the board H is rocked to the position shown in Figure 2, the right-hand control mechanism 30 will be compressed in the manner shown in Figure 5. In

tially horizontal position. If desired, similar adjustments may be made on one or both of the controlling mechanisms or the adjustments can be made in opposite directions on each of the controlling mechanisms. Referring specifically to Figure l, which shows the control mechanism assembly in its normal position of rest, it will be seen that if the lock nuts 39 and ii are raised, this will compress spring which will in turn push cylinder 33 upwardly, thus tilting the board i I in a clockwise direction, as shown in Figure 2. When the board is tilted in this direction, the cylinder 33' of the other control mechanism will be pressed downwardly thereby compressing spring 35 of this control mechanism. The ultimate position of the body M will be determined when the force exerted by each of the springs 35 balance one another. Conversely, the double lock nuts 39 and ill may be lowered on the rod 38, thereby normal'ly tending to compressspring 35. This in turn will cause the cylinder 33 to be lowered, thus tilting the board H in a counterclockwise direction. This action on the right-hand control mechanism will, in turn, tend to compress lower spring 38 so that the ultimate position of the board will be determined-when the springs 36 of each control mechanism balance each other.

As shown in Figures 1, 2 and 6, and in detail in Figure 7, a locking mechanism 45 is provided to prevent rotation of the board H in the horizontal plane, thus restricting the use of the device to a teeter-totter or see-saw. The mechanism 45 comprises a slidable bolt 55 disposed this position the cylinder 33 has been pushed cylinder 33 is raised upward so that the piston 3'4 moves against and; compresses the lower spring 36. Thus, it will. be seen that when the board is in the position shown in Figure 2, the lower spring 38 of the lefthand control mechanism and the upper spring 35 of the right-hand control mechanism 323', both tend to urge the board. H back to the normal position.

According to the present invention, the lower springs 36 have greater strength than the upper springs 35. For example, the lower springs 36 may have a compression of 145 pounds per inch, while the upper springs 35 may have a compression of pounds per inch.

When the amusement device is to be used by persons having substantially the same weight, the adjustable lock nuts 39 and ii) on rods 33 of the control mechanisms 38 will be at that position where the springs 35 and 35 will not be compressed when the board I! is in the normal substantially horizontal position. When the teeter device is being used, substantially the same force will be applied by the springs 35 or 36 whether the board has been tilted to the right or the left.

When the teeter device is to be used by persons having unequal weights, the weight of the heavier person may be compensated for by adjusting the double lock nuts 39 and, 40 so that the position ofthe board at rest will be at an angle to the horizontal. In this way two persons of unequal weight will offset the angle of the board at rest so that the two'persons when seated on the endsof the board will bring the board into a substanwithin a housing 41! secured to the outside of shaft Hi. The bolt is adapted to slide into hole 68 provided in a rotatable shaft Hi and one of the holes .9 provided in fixed shaft 25 when the hole d8 registers with one of them.

The bolt 46 is provided with a depending lug 58 which is slidable between flanges 5| and 52' of the housing member 41. A stop 53 for the lug 5B is provided to prevent the bolt 46 from being entirely withdrawn from the housing ti. The lug 5B is provided with a hole 5 2 which will register with either of holes 55 provided in the flanges 51 and 52 depending, on the position of the bolt 45. When the hole M is registered with one of the holes 55, a tethered locking pin 5'5 can be inserted to secure the bolt 46 in the desired position. When the bolt is partially withdrawn so as not to engage the hole 49, the teeter can be used as a merry-go-round; whereas when fully inserted the bolt 16 will engage one of the holes 59, as shown in Figure 7, and will prevent the mery-go-round movement so the device can be used onlyas a teeter-totter.

While the present invention has been described with particular reference to the modification illustrated in the attached drawings, it will be understood that the invention is not limited thereby and that various modifications which would be obvious to a man skilled in the art, are to be included within the scope of this invention. For,- example, suitable lubrication fittings and various mechanical equivalents may be used withoutdeparting from the spirit and scope of the present invention, which is defined by the appended claims.

What is claimed is:

1. In an amusement device havin a teeter board mounted on a support adjacent its longitudinal center so as. to rotatein a. vertical plane, a pair of spring controlled mechanisms for resisting rotation Of'th. board located one on each side of the center of rotation thereof, each of said mechanisms being connected to the teeter board and to the support and comprising a light compression spring and a heavy compression spring in mutually opposed relation and means therebetween for compressing said springs one at a time When the board is rotated in alternate directions, said compressing means being adjustable to vary the compression of one of said springs, the compressing means of both mechanisms bein adjusted so that the light spring of one mechanism will be compressed during initial rotation of the board and the heavy spring of the other mechanism will be compressed during further rotation of the board in the same direction.

2. A device as claimed in claim 1 wherein each of said mechanisms also comprises a cylinder within which said springs are disposed, and wherein the compressing means of each mechanism comprises a piston slidably within the cylinder and between the springs.

B. A device as claimed in claim 2 wherein each cylinder is connected to the teeter board at a point removed from the axis of rotation thereof and each piston is connected to the support.

4. A device as claimed in claim 1 wherein the compressing means of each mechanism maintains the light spring thereof under compression when said board is at rest.

ARTHUR E. PROBS'I.

REFERENCES CITED The following references are of record in the file of this patent:

v UNITED STATES PATENTS Number 

